What I can remember is it was a slasher flick. I think it was a family in a house and through the movie someone kept spying on the girl or girls that stayed in the house using night vision goggles, at least the vision was green. Might have been just green lens but it was always green when the person was spying. I believe he was spying from a corn field or a fruit tree field in the backyard of the house. Through the movie people kept getting killed and you never saw who it was. They always used the vision to spy and imply it was the killer. Turns out at the end of the movie they found out one of the perverted relatives or someone in the house was spying but it was a different person that was killing everyone (the twist) and he stormed in the house at the end and they killed him. it was a slasher of some kind like Jason.

I was alot younger when it was on tv and never remembered the names. It was on either HBO, Cinemax or Showtime constantly around 1989-1991 time frame. I'm guessing it was made sometime around then or before.

Any help would be appreciated.. I've searched 100's of horror titles from this era and still no luck. English US movie.